摘要：

In this study, Fe3O4 nanoparticles (NPs) as a core surrounded with thick and tunable SiO2 shells were successfully synthesized and characterized by means of N-2-isotherm, scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), fourier transform infrared (FT-IR) and UV-Vis diffuse reflection spectroscopy (UV-Vis DRS) techniques. The characterization results revealed that well-structured SiO2 shell of 105 nm thick is uniformly formed around Fe3O4 (NPs size of 500 nm) surface. The application of the synthesized core-shell structures was investigated for methylene blue (MB), rhodamine B (Rh B) and methyl orange (MO) toxic dyes adsorptive removal from water by batch adsorption methods and different adsorption parameters such as time, pH, material dosage, concentration of solution and different dyes were optimized. The highest adsorption capacity (123 mg g(-1)) of MB dye was achieved on Fe3O4@SiO2. The isotherms and kinetic models exhibited that MB adsorption values are well described by Freundlich isotherm and pseudo-first-order kinetics models. The adsorptive binding of MB with Fe3O4@SiO2 was directed through electrostatic interaction and size filter effect. After regeneration, approximately 100% MB dye adsorption capacity was recovered. Thus, we can say that the Fe3O4@SiO2 is an outstanding material for dyes removal from water.

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